Payload is the object or the entity that is being carried by an

aircraft An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...

launch vehicle A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multistage ...

. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of the flight or mission, the payload of a vehicle may include

cargo In transportation, cargo refers to goods transported by land, water or air, while freight refers to its conveyance. In economics, freight refers to goods transported at a freight rate for commercial gain. The term cargo is also used in cas ...

passenger A passenger is a person who travels in a vehicle, but does not bear any responsibility for the tasks required for that vehicle to arrive at its destination or otherwise operate the vehicle, and is not a steward. The vehicles may be bicycles, ...

s, flight crew,

munition Ammunition, also known as ammo, is the material fired, scattered, dropped, or detonated from any weapon or weapon system. The term includes both expendable weapons (e.g., bombs, missiles, grenades, land mines), and the component parts of oth ...

s, scientific instruments or experiments, or other equipment. Extra fuel, when optionally carried, is also considered part of the payload. In a commercial context (i.e., an

airline An airline is a company that provides civil aviation, air transport services for traveling passengers or freight (cargo). Airlines use aircraft to supply these services and may form partnerships or Airline alliance, alliances with other airlines ...

or air freight carrier), payload may refer only to revenue-generating cargo or paying passengers. A payload of ordnance carried by a combat aircraft is sometimes alternatively referred to as the aircraft's warload. For a rocket, the payload can be a

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

space probe Uncrewed spacecraft or robotic spacecraft are spacecraft without people on board. Uncrewed spacecraft may have varying levels of autonomy from human input, such as remote control, or remote guidance. They may also be autonomous, in which th ...

, or

spacecraft A spacecraft is a vehicle that is designed spaceflight, to fly and operate in outer space. Spacecraft are used for a variety of purposes, including Telecommunications, communications, Earth observation satellite, Earth observation, Weather s ...

carrying humans, animals, or cargo. For a

ballistic missile A ballistic missile is a type of missile that uses projectile motion to deliver warheads on a target. These weapons are powered only during relatively brief periods—most of the flight is unpowered. Short-range ballistic missiles (SRBM) typic ...

, the payload is one or more

warhead A warhead is the section of a device that contains the explosive agent or toxic (biological, chemical, or nuclear) material that is delivered by a missile, rocket (weapon), rocket, torpedo, or bomb. Classification Types of warheads include: *E ...

s and related systems; their total weight is referred to as the throw-weight. The fraction of payload to the total liftoff weight of the air or spacecraft is known as the " payload fraction". When the weight of the payload and fuel are considered together, it is known as the " useful load fraction". In spacecraft, "mass fraction" is normally used, which is the ratio of payload to everything else, including the rocket structure.

Relationship of range and payload

There is a natural trade-off between the payload and the range of an aircraft. A payload range diagram (also known as the "elbow chart") illustrates the trade-off. The top horizontal line represents the maximum payload. It is limited structurally by maximum zero-fuel weight (MZFW) of the aircraft. Maximum payload is the difference between maximum zero-fuel weight and operational empty weight (OEW). Moving left-to-right along the line shows the constant maximum payload as the range increases. More fuel needs to be added for more range. The vertical line represents the range at which the combined weight of the aircraft, maximum payload and needed fuel reaches the maximum take-off weight (MTOW) of the aircraft. If the range is increased beyond that point, payload has to be sacrificed for fuel. The maximum take-off weight is limited by a combination of the maximum net power of the engines and the lift/drag ratio of the wings. The diagonal line after the range-at-maximum-payload point shows how reducing the payload allows increasing the fuel (and range) when taking off with the maximum take-off weight. The second kink in the curve represents the point at which the maximum fuel capacity is reached. Flying further than that point means that the payload has to be reduced further, for an even lesser increase in range. The absolute range is thus the range at which an aircraft can fly with maximum possible fuel without carrying any payload.

Examples

Examples of payload capacity: *

de Havilland Mosquito The de Havilland DH.98 Mosquito is a British twin-engined, multirole combat aircraft, introduced during the World War II, Second World War. Unusual in that its airframe was constructed mostly of wood, it was nicknamed the "Wooden Wonder", or " ...

B Mk.IV Series 2: 920 kg *

Boeing B-17 Flying Fortress The Boeing B-17 Flying Fortress is an American four-engined heavy bomber aircraft developed in the 1930s for the United States Army Air Corps (USAAC). A fast and high-flying bomber, the B-17 dropped more bombs than any other aircraft during ...

: 1,800 kg (typical long range missions), 3,600 kg or more (short range missions) * Petlyakov Pe-8 4,990 kg (internal) * B-52H Stratofortress: 31,500 kg * Antonov An-225 ''Mriya'': 250,000 kg * Saturn V: **Payload to

Low Earth Orbit A low Earth orbit (LEO) is an geocentric orbit, orbit around Earth with a orbital period, period of 128 minutes or less (making at least 11.25 orbits per day) and an orbital eccentricity, eccentricity less than 0.25. Most of the artificial object ...

140,000 kg **Payload to Lunar orbit 47,000 kg *

Space Shuttle The Space Shuttle is a retired, partially reusable launch system, reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. ...

: **Payload to Low Earth Orbit (Not counting the 110,000 kg serviced orbiter) 27,000 kg (53,700 lb) **Payload to geostationary transfer orbit (Not counting the 110,000 kg serviced orbiter) 3,810 kg (8,390 lb) *

Trident (missile) The Trident missile is a submarine-launched ballistic missile (SLBM) equipped with multiple independently targetable reentry vehicles (MIRV). Originally developed by Lockheed Missiles and Space Corporation, the missile is armed with thermonucle ...

: 2800 kg throw weight * Automated Transfer Vehicle **Payload: 7,667 kg 8 racks with 2 x 0.314 m³ and 2 x 0.414 m³ **Envelope: each 1.146 m³ in front of 4 of these 8 racks **Cargo mass: Dry cargo: 1,500 - 5,500 kg **Water: 0 – 840 kg **Gas (Nitrogen, Oxygen, air, 2 gases/flight): 0 – 100 kg **ISS Refueling propellant: 0 – 860 kg (306 kg of fuel, 554 kg of oxidizer) **ISS re-boost and attitude control propellant: 0 - 4,700 kg **Total cargo upload capacity: 7,667 kg

Structural capacity

For aircraft, the weight of fuel in wing tanks does not contribute as significantly to the bending moment of the wing as does weight in the fuselage. So even when the airplane has been loaded with its maximum payload that the wings can support, it can still carry a significant amount of fuel.

Payload constraints

Launch and transport system differ not only on the payload that can be carried but also in the stresses and other factors placed on the payload. The payload must not only be lifted to its target, it must also arrive safely, whether elsewhere on the surface of the Earth or a specific orbit. To ensure this the payload, such as a warhead or satellite, is designed to withstand certain amounts of various types of "punishment" on the way to its destination. Most rocket payloads are fitted within a payload fairing to protect them against dynamic pressure of high-velocity travel through the atmosphere, and to improve the overall aerodynamics of the launch vehicle. Most aircraft payloads are carried within the

fuselage The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...

for similar reasons. Outsize cargo may require a fuselage with unusual proportions, such as the Super Guppy. The various constraints placed on the launch system can be roughly categorized into those that cause physical damage to the payload and those that can damage its electronic or chemical makeup. Examples of physical damage include extreme accelerations over short time scales caused by atmospheric buffeting or oscillations, extreme accelerations over longer time scales caused by rocket thrust and gravity, and sudden changes in the magnitude or direction of the acceleration caused by how quick engines are throttled and shut down, etc. Electrical, chemical, or biological payloads can be damaged by extreme temperatures (hot or cold), rapid changes in temperature or pressure, contact with fast moving air streams causing ionization, and radiation exposure from

cosmic ray Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the ...

s, the van Allen belt, or

solar wind The solar wind is a stream of charged particles released from the Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy betwee ...

References

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